The thermally hydrated dipalmitoyl phosphatidyl choline (DPPC) Langmuir (L) Nm was investigated to determine whether it could be an appropriate physical model of DPPC liposomes. The interaction of sucrose with the L film and the liposome was investigated for the examination. The conventional DPPC L film without any heating process showed a film shrinkage by bound sucrose on the surface of the L film. The film shrinkage was enhanced with an increase of the concentration of sucrose. This shrinkage was found to affect all of the entire characteristics of the conventional L film. On the other hand, the hydrated L film by a heating process indicated a film expansion by the penetrated sucrose, although the incorporated water in the film avoided the approach of sucrose a little. The expansion increased with the concentration of sucrose, a fact that was contrary to the results of the conventional L film. To compare the hydrated L film with liposome, the fluorescence decay and anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH) in DPPC liposomes were measured. The results indicated that the molecular order of DPPC in the liposome decreased with the concentration of sucrose. The molecular motion of DPPC was reduced with the concentration of sucrose. These phenomena were successfully explained by the results of the hydrated L films. The hydrated L film was consequently proposed to be a much better physical model of liposomes than the conventional L film.